AndroidAn Android client which allows you to do offline reviews, as well as syncing with the desktop client, is available from Google Play. In case Google Play is blocked in your country (e.g. China), you can also download it here.

For mobile review on other platforms, activate the Mnemosyne webserver on your desktop (requires 2.3) using the configuration screen, and then review using your browser on your mobile client.

(For Windows phone, there is also ColibriM, which is a non-free client which is not developed by the Mnemosyne project. ColibriM relies on Mnemogogo.)